Comparison of Centrifuge and Freezing Calorimeter Methods for Measuring Free Water in Snow,

摘要

In using microwave measurements in hydrological studies of snowpack or avalanche prediction,the presence of free water in the snow has a strong influence on observed data because it affects the dielectric characteristics. Although several methods are in use for determining the percentage of free water in snow,there is very little information in the literature as to how well the various methods agree. This paper reports on a comparison of two popular methods;namely,the centrifuge and the freezing calorimeter. Results from measurements over a two-month period in the Colorado mountains in the winter of 1978indicate serious disagreement between these two methods. Some reasons for the disagreement are presented and verified. This raises some important questions pertaining not only to what the two methods actually measure,but also which methods may be appropriate for particular applications.